Memristor based storage of asset events

ABSTRACT

An example device comprising contactless circuitry to receive data about a plurality of events corresponding to an asset, and a memristor coupled to the contactless circuitry to store the data about the plurality of events. The contactless circuitry may determine that the asset has experienced an event, receive a transaction corresponding to the event from a decentralized entity, generate a hash of the transaction including a device identifier of the contactless circuitry and the transaction received from the decentralized entity, verify the hashed transaction with the decentralized entity, and store the verified hashed transaction on the memristor of the contactless circuitry, wherein the stored verified hash includes information about the event.

BACKGROUND

Provenance records of assets may be tracked to determine the origin ofthe assets and modifications of the assets. The provenance records maybe stored as heuristic records in computing devices. The heuristicrecords may be used to determine if an asset is authentic and/or if ithas been altered. The heuristic record may track the asset from itsgeneration until the end of its lifecycle.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates an example device including a memristor for memristorbased storage of asset events consistent with the disclosure.

FIG. 2 illustrates an example contactless circuitry including amemristor for memristor based storage of asset events consistent withthe disclosure.

FIG. 3 illustrates an example decentralized entity and an examplememristor for memristor based storage of asset events consistent withthe disclosure.

FIG. 4 illustrates an example message flow schematic for memristor basedstorage of asset events consistent with the disclosure.

FIG. 5 illustrates an example memristor coupled to programming circuitryfor memristor based storage of asset events consistent with thedisclosure.

DETAILED DESCRIPTION

Assets such as manufactured products, food, drink, pharmaceuticals,computing devices, clothing, etc. may experience multiple events duringthe lifecycle of the asset. As used herein, the term “event” refers toan occurrence which affects an asset. Some examples, of events includethe generation or an asset, a change in ownership, a change ingeographical location, a change in state of the asset, etc. The eventsmay alter the physical characteristics, the geographical location, theownership, a change in state, etc. or a combination thereof. Assets maybe tracked from the genesis of the asset to the end of the life of theasset. The end of life for an asset may be when the asset is obtained byan end user, is destroyed, consumed, etc. As used herein, the term“lifecyle” refers to the life of the asset from genesis to the end ofthe life of the asset. The tracking of assets may be used to detectwhen/if an asset has experienced an event.

For example, asset tracking may be used for many applications of supplychain logistics to track data about the creation of the asset, dataabout shipment of the asset, installation of the asset into anotherasset (a microchip installed into a computing device), ownership of theproduct, etc. Further, the end user of the product may be interested intracking the provenance records of the product to establish where theasset was created, amongst other information. In the field of foodand/or pharmaceutical production, provenance information of a productmay be used to determine product recall information. For asset tracking,transactions corresponding to events experienced by the asset may bestored as an immutable record in a decentralized entity.

As used herein, the term “decentralized entity” refers to anopen-source, distributed computing platform. In some examples, adecentralized entity may be a part of a public platform such as a publiccloud. In some examples, the decentralized entity may be deployed on aprivate network such as a private cloud. The decentralized entity mayinclude distributed ledger technology (DLT). The DLT includes aconsensus of replicated, shared, and synchronized digital data which maybe spread across multiple computing devices. In some examples, thedecentralized entity may be a blockchain-based distributed computingplatform. For example, a block of the blockchain may include informationand may be added to a blockchain as an immutable record, the blocks maybe linked together utilizing a hash function applied to the informationabout the event and the transaction. As sued herein, the term“transaction” refers to information and/or data which may be verified,encrypted, and stored as a block. As used herein, the term “hashfunction” refers to a cryptographic series of numbers and characters toact as a digital fingerprint applied to a piece of information to securethe information, prevent error, and/or be stored with a transaction. Thetransactions stored in the blockchain track the provenance informationof an asset because the transaction includes information correspondingto the asset. The information about the asset may correspond to a devicecoupled to the asset.

As used herein, the term “device” refers to a physical carrier ofcontactless circuitry which may be bonded to an asset. The device bondedto the asset may include circuitry such that it may communicate withother devices and/or the blockchain. Some examples, of devices arecards, smartcards, microchips, etc. Devices used for asset tracking maybe small enough to be woven into materials of the asset, or otherwiseinconspicuously bonded to the asset. When the device is bonded to theasset, it may provide identifying information about the asset andcommunicate when an event has occurred, is occurring, and/or will occursuch that the records of the events may be stored in the blockchain. Inthis way, a user in possession of the asset may use the device coupledto the asset to as a key to obtain information about the asset in thedigital system of the decentralized entity. This results in a systemthat is secure but has limited security guarantees because the assetverification and queries on the provenance of the asset rely on anindividual hash function. In other words, the asset itself does notinclude any data to verify the provenance records in the device coupledto the asset. It may be technically challenging to store secureprovenance records about the assets in the devices.

As such, examples discussed herein provide examples, of devices coupledto assets to track the provenance information of the assets and securelystore the events on the device coupled to the asset itself. In this way,the asset is involved with every transaction created in response to anevent. For example, as each transaction is stored as a block in theblockchain, another record is created, encrypted, and securely stored asa local block on the device coupled to the asset. Devices such assmartcards include a storage device (e.g., EEPROM) that is not largeenough to include such provenance records. As such examples, hereindescribe devices created to include a memristor storage device in placeof a smaller storage device (e.g., EEPROM).

As used herein, the term “memristor” refers to a non-volatile, randomaccess, memory component with read and write storage capabilities, basedon resistive memory properties. A memristor may utilize a similarfootprint and utilize a similar energy demand as a smaller memorycapacity device such as an EEPROM. However, a memristor may include alarger memory capacity when compared to other memory storage devicessuch as EEPROM. For example, a memristor may provide increased storagedue to the higher packing densities that memristors can achieve on thesame or comparable on-chip real estate (e.g., footprint). Additionally,memristors may not demand a large amount of power to write thememristors base memory. Therefore, the size of the device may notincrease due to the addition of a memristor. Specifically, the memristormay be coupled to contactless circuitry included in the device where thecontactless circuitry is to determine when an asset has experienced anevent, receive a transaction from a decentralized entity about theevent, encrypt the transaction, verify that the event is valid, andstore the event as an immutable record in the decentralized entity andin the device coupled to the asset.

FIG. 1 illustrates an example device 100 including a memristor 104 formemristor based storage of asset events consistent with the disclosure.FIG. 1 illustrates a device 100 including contactless circuitry 102, anda memristor 104. The device 100 may be coupled to a decentralized entity106, and an asset 108. As used herein, the terms “in contact,”“connected,” and/or “coupled to” refer to an element which may bedirectly in contact, connected, or coupled with the other element. Forexample, the device 100 may be connected to the decentralized entity 106via a radio frequency and/or a wireless connection between thedecentralized entity 106 and the contactless circuitry 102 of the device100. The asset 108 may be connected to the device 100 directly. Forexample, the device 100 may be a card that is directly bonded to theasset 108. As used herein, the term “bonded” refers to a powerfuladhesion of two elements.

For example, the device 100 may be bonded to the asset 108 such that theasset 108 and the device 100 appear to be an individual portion of theasset 108. In other words, the device 100 may be bonded to the asset 108such that the device 100 is inconspicuous and may appear to be apart ofthe asset 108. In some examples, the device 100 may be fused to theasset 108 such that the device is a permanent addition to the asset 108.For example, the device 100 may be molded into the asset 108 such thatthe removal of the device 100 may render the asset 108 damaged. Thedevice 100 may be flexible such that it may be woven into a fabric whenthe fabric is part of the asset 108. The device 100 includes contactlesscircuitry 102 to enables the device 100 to communicate.

As used herein, the term “contactless circuitry” refers to circuitrythat enables contactless communication between devices. For example, thecontactless circuitry 102 may include embedded integrated circuits whichmay store and/or process data and communicate with a terminal of anotherdevice using near-field communication. For example, the contactlesscircuitry 102 of the device 100 may receive data about a plurality ofevents corresponding to the asset 108. For example, the plurality ofevents may be events that are a part of the lifecycle of the asset 108.The lifecycle of the asset 108 includes the genesis of the asset 108until the asset 108 is used by an end user, and/or destroyed, etc.Specifically, the initial event of an assets 108 lifecycle may be theinstance it is created (e.g., when a processor is manufactured), a firstevent may be when the asset 108 is physically altered (e.g., theprocessor is installed into a laptop), and a subsequent event (e.g., asecond event) may be when the asset 108 is shipped to a differentlocation (e.g., the laptop is shipped to a wholesaler), etc. In otherwords, the plurality of events may be, physical modifications of theasset 108, changes of a location of the asset 108, a change in state ofthe asset 108, a change in ownership of the asset 108, or combinationsthereof. The contactless circuitry 102 includes a memristor 104 to storeinformation about the plurality of events.

For example, the memristor 104 is coupled to the contactless circuitry102 to store the data about the plurality of events. Specifically, thememristor 104 may store each event of the plurality of events as averified hashed transaction on the memristor 104 in sequential order.For example, when the device 100 is initially bonded to the asset 108,the contactless circuitry 102 may generate a digital image of the asset108 to be stored in the decentralized entity 106 and the memristor 104when the asset 108 is coupled to the device 100. This may be the initialevent which may be the first block stored in the decentralized entity106 and stored as a local block in the memristor 104. As used herein,the term “local block” refers to the encrypted secure block ofinformation that is stored in the memristor 104. A local block may bestored in the memristor 104 as a provenance record of an eventexperienced by the asset 108. For example, the memristor 104 may operateas a local blockchain coupled to the asset 108. Specifically, thecontactless circuitry 102 may apply a hash function (e.g., hash) dataabout the asset 108, the transaction, and the transaction that may haveoccurred before the current transaction in a similar manner as ablockchain except on the asset 108 itself. This is discussed in furtherdetail in connection with FIG. 3. Part of the information hashed by thecontactless circuitry 102 may be a unique identifier of the contactlesscircuitry 102.

For example, the device 100 may be coupled to the asset 108, and thetransaction may include a unique device identifier (device ID)corresponding to the contactless circuitry 102 and the asset 108 towhich the contactless circuitry 102 is coupled. As used herein, the term“device identification” (device ID) refers to the unique identifiercorresponding to the contactless circuitry 102 included on the device100. The contactless circuitry 102 of the device 100 may be encryptedand stored with the transaction that creates the digital image of theasset 108 when the device 100 is bonded to the asset 108. The generationof the secure device ID with the digital image of the asset 108 may bestored as an initial block in the decentralized entity 106 correspondingto the asset 108. To create an immutable provenance record coupled tothe asset 108 itself, the contactless circuitry 102 may utilize thememristor 104 to store a local block including the secure device ID withthe digital image of the asset 108. In this way, the initial immutablerecord stored both in the decentralized entity 106 and the memristor 104is a record identifying the contactless circuitry 102 and the asset 108to which it is coupled. The device ID may be included as part of thehash when the asset 108 experiences events.

For example, the contactless circuitry 102 may determine that the asset108 has experienced an event. In some examples, the contactlesscircuitry 102 may determine that the asset 108 has experienced an eventvia a radio frequency identification (RF) interface. For example, thecontactless circuitry 102 may include a RF interface and contactlesscommunication functionality, where the RF interface may identify theevent by receiving and/or transmitting radio signals between deviceswirelessly. In response to the determined event, the contactlesscircuitry 102 may receive a transaction corresponding to the event fromthe decentralized entity 106. For example, the contactless circuitry 102may receive a unique transaction identifier about the event.Specifically, if the asset 108 is a processor, the event may be when theprocessor is moved from the factory floor to a logistics site, so theunique transaction identifier may be information about the movement ofthe processor (e.g., the asset 108) from the factory to the logisticssite. The contactless circuitry 102 may then apply a secure hash to thetransaction.

In some examples, the contactless circuitry 102 may generate a hashincluding the unique device ID of the contactless circuitry 102 and thetransaction received from the decentralized entity 106. The transactionmay be received from the decentralized entity 106, or the transactionmay be extracted from the decentralized entity 106. In other words, thehash generated by the contactless circuitry 102 includes the sametransaction used by the decentralized entity 106 to create a block to bestored as an immutable record. The hash created by the contactlesscircuitry 102 includes the transaction corresponding to the event,either received or extracted from the decentralized entity 106, theunique device ID, a random number (e.g., a nonce), and the hash functionfrom the previous transaction. In advance of storing the transaction asa block in the decentralized entity 106 or as a local block in thememristor 104 coupled to the asset 108, the transaction may be verified.

For example, the contactless circuitry 102 may verify the hashedtransaction with the decentralized entity 106. For example, thecontactless circuitry 102 may verify the hashed transaction by comparingthe hashed transaction with a condition of a smart contract deployed onthe decentralized entity 106. As used herein, the term “smart contract”is a protocol to digitally facilitate, verify, and/or enforce anegotiation and/or a performance of information in credibletransactions. The smart contract may reside on the decentralized entity106 which may include a distributed ledger technology (DLT), (e.g., ablockchain with smart contract capabilities) such that the smartcontract may be accessed by the device 100 (and/or the contactlesscircuitry 102). A smart contract may be created by an entity with aninterest in the asset 108 (e.g., a manufacture, an end user, apurchaser, etc.) these entities may create, modify, delete or otherwiseupdate provisions (e.g., specifying a condition such as particularallowed event, dates, times, geographical areas, etc.) using at leastone smart contract. In this way, the event may be controlled, andsanctioned by the device in exchange for a reward upon mutual agreement.Further, by leveraging the decentralized entity 106 with smart contractcapability, the immutable record of the transaction can be digitallyverified as the events alter the asset 108, and the immutable record maybe locally stored in the memristor 104.

For example, the contactless circuitry 102 may store the verified hashedtransaction on the memristor 104 of the contactless circuitry 102, wherethe stored verified hash includes information about the event. Theverified hash transaction may be secure and encrypted and stored as alocal block in the memristor 104. In response to the verification by thedecentralized entity 106, the asset 108 may be modified and an approvaltransaction identification may be transmitted to the contactlesscircuitry 102, which may be securely stored with the hashed transaction.As mentioned, the contactless circuitry 102 may store the verified hashtransaction as an immutable record in the decentralized entity 106 andthe memristor 104. In other words, the verified hashed transaction maybe stored as a block, and the block may include information about thetransaction preceding, and this may be stored as an immutable record inthe blockchain. The same information may also be stored as an immutablerecord (e.g., a local block) on the memristor 104 coupled to the asset108. In this way, the asset 108 may be meshed with the blockchain(decentralized entity 106), such that the memristor 104 may store averified hashed transaction record corresponding to each event of theplurality of events. Examples described herein may apply to the creationof a new asset which includes an existing asset and/or collection ofexisting assets (e.g., creating a computing device including existingassets).

For example, as mentioned, a first event may include an initial instancewhen the asset 108 is bonded to the device 100. A subsequent event maybe a second event which may include the asset 108 being integrated intoa different asset. For example, if a first asset 108 is a processor, thefirst event may be when the processor is bonded to a first device 100. Asecond event may be the processor being integrated into a second assete.g., a computing device, where the computing device may be bonded to asecond device (e.g., similar to the device 100). In this example, thecomputing device may be a second asset comprising the first asset 108(e.g., the processor) bonded to the first device 100. As such, a firstevent experienced by the second asset (the computing device) may be theinstance when the first asset 108 (the processor) is integrated into thecomputing device. Thus, the first transaction for the computing devicemay include information about the processor (e.g., the first asset 108).Since the first asset 108 (the processor) and the second asset (thecomputing device) both include a device (e.g., the device 100) they bothmay utilize a memristor based event storage to leverage secureencryption of provenance records. As such, examples described herein maybe applied to a new asset (the computing device) which may include anexisting asset 108 (e.g., the processor) and/or a plurality of existingassets (e.g., other components of the computing device).

The examples described in connection with FIG. 1 describe memristor 104based storage of asset events where the provenance records of an assetare stored in sequential order as the data is stored on a decentralizedentity 106. A device 100 including contactless circuitry 102 with amemristor 104 securely bonded to the asset 108 meshes the asset 108itself with provenance records that were otherwise stored separately inthe decentralized entity 106. Leveraging secure encryption included withthe contactless circuitry 102 with the storage capabilities of thememristor 104 provides a layer of security otherwise not available.

FIG. 2 illustrates an example contactless circuitry 202 including amemristor 204 for memristor based storage of asset events consistentwith the disclosure. The contactless circuitry 202 illustrated in FIG. 2includes a radio frequency (RF) interface 210, a power on reset 212, avoltage regulator 214, an input filter 216, a reset generator 218, areceiver/transmitter 220, programming circuitry 222, an encryption unit224, a random number generator (RNG) 226, cyclic redundancy check 228,and a memristor 204. Although not illustrated in FIG. 2 as to notobscure the examples of the disclosure, the contactless circuitry 202may be included in a device (e.g., the device 100) bonded to an asset(e.g., the asset 108). FIG. 2 illustrates the memristor 204 integratedwith other components of the contactless circuitry 202.

The integration of the memristor 204 into the contactless circuitry 202provides an on-chip storage of provenance records. As mentioned, thecontactless circuitry 202 may include a RF frequency interface 210. Insome examples, the RF frequency interface 210 may include an antennathan enables the RF frequency interface 210 to transmit the device ID toan RF frequency interface reader. For example, the RF frequencyinterface 210 may transmit the unique device ID of the contactlesscircuitry 202 and to identify that an event. In other words, during anevent, the RF frequency interface 210 may be positioned within range ofan RF reader (e.g., the asset may be scanned by an RF reader) so thatthe event may be verified and stored in a decentralized entity (e.g.,the decentralized entity 106) and the memristor 204. The RF frequencyinterface 120 may be coupled to circuitry used to reset the power to thecontactless circuitry 202.

For example, the contactless circuitry 202 may include a power on reset212, and a reset generator 218. As used herein the term “power on reset”refers to a microcontroller or microprocessor that ensures that thedevice operates in a known state in response to a reset signal. As usedherein, the term “reset generator” refers to a microcontroller ormicroprocessor that generates a reset signal when power is applied tothe device. For example, the reset generator 218 may generate a resetsignal when the contactless circuitry 202 is to be reset. Thus, thepower on reset 212 may restore the restarted contactless circuitry 202to a known state such that it may continue to verify, encrypt, and storetransactions as a local block in the memristor 204. The contactlesscircuitry 202 may also include a voltage regulator 214 and an inputfilter 216.

As used herein, the term “voltage regulator” refers to a system designedto maintain a constant voltage. For example, the voltage regulator 214may protect the contactless circuitry 202 from a harmful amount ofvoltage which may damage the contactless circuitry 202 components. Asused herein, the term “input filter” refers to an electrical componentthat eliminates extraneous pulses on input lines. An example of an inputfilter may be a clock input filter to set delays to filter signalsduring periods of low passage and high passage signal transmission. Thecontactless circuitry 202 may include a receiver/transmitter 220 andprogramming circuitry 222.

In some examples, the receiver/transmitter 220 may be a computerhardware device for communication between devices. For example, thereceiver/transmitter may be a universal asynchronousreceiver-transmitter (UART). A UART may provide serial communication forthe contactless circuitry 202. The receiver/transmitter 220 may havedata format and transmission speeds that may be altered or set by theprogramming circuitry 222. As used herein, the term “programmingcircuitry” refers to a programmable logic device which may executeprogrammed instructions. For example, the programming circuitry 222 maybe an integrated circuit such as field programmable gate array (FPGA),an application specific integrated circuit (ASIC). The instructions maybe programmed prior to installation in the device, or while theprogramming circuitry 222 is installed in the device. For example, theprogramming circuitry 222 may include instructions to securely storeprovenance information in the memristor 204 as a local block.

For example, the contactless circuitry 202 may include an encryptionunit 224. As used herein, the term “encryption unit” refers to acomponent used to convert data into a code to secure the data. In someexamples, the encryption unit may execute secure encryption usingCRYPTO-1 or similar. The encryption unit 224 may be used to encrypt thetransaction provided by a decentralized entity in response to an event.The encryption unit 224 may be used to provide encryption to each of aplurality of events in response to the asset which is coupled to thecontactless circuitry 202 having experienced an event. As mentioned, theencryption unit 224 may provide secure encryption to the transactions,and the encrypted transaction may be used as a portion of a hash with arandom number generated by the random number generator 226.

For example, a random number generator 226 may generate a random number(RNG) and may be a component that generates a sequence of numbers and/orsymbols whose probability of predictability are not better than randomchance. In some examples, the RNG generated by the random numbergenerator 226 may be a nonce. The random number generator 226 mayproduce an RNG may be a hardware random number generator, or apseudo-random number generator. The contactless circuitry 202 may alsoinclude a cyclic redundancy check 228 (CRC). As used herein, the term“cyclic redundancy check” (CRC) refers to an error detecting code usedin digital networks and storage devices to detect changes to data. TheCRC 228 may be used to detect error caused by noisy transmissionchannels. The components of the contactless circuitry 202 may be used tosecurely store the transactions describing provenance records of theasset as a local block in the memristor 204. The memristor 204 may be ofa size that it may fit on the contactless circuitry 202 such that thecontactless circuitry 202 may operate as a chip with smartcardcapabilities. In other words, the contactless circuitry 202 may operateas a smartcard with the added functionality to store larger pieces ofdata (local blocks) in sequential order on the memristor 204. Becausethe contactless circuitry 202 is part of a device that is securelybonded to the asset itself, the asset is meshed with the secureprovenance records about the asset.

The examples described in connection with FIG. 2 describe memristor 204based storage of asset events where the provenance records of an assetare stored in sequential order as the data is stored on a decentralizedentity. The memristor 204 is a part of the contactless circuitry 202 andis integrated on the contactless circuitry 202 such that the provenancerecords may be stored on-chip. The ability to store provenance recordinformation on-chip via the memristor 204 provides increased securitywhen compared to contactless circuitry absent memristor 204 storagecapabilities. Additionally, storing provenance records as local blockson the memristor 204 mesh the asset itself into the provenance recordsbecause the contactless circuitry is bonded to the asset via a device(e.g., a smartcard).

FIG. 3 illustrates an example decentralized entity 306 and an examplememristor 304 for memristor based storage of asset events consistentwith the disclosure. FIG. 3 illustrates a decentralized entity 306(e.g., a blockchain) including a plurality of blocks 330, 332, 334, and336, each representing a stored record of a plurality of events. FIG. 3illustrates a memristor 304 including a plurality of local blocks 338,340, 342, and 344, each representing a stored record of a plurality ofevents. Although not pictured in FIG. 3 as to not obscure examples ofthe disclosure, the memristor 304 may be a part of contactless circuitry(e.g., the contactless circuitry 202) coupled to a device (e.g., thedevice 100) bonded to an asset (e.g., the asset 108), the contactlesscircuitry and the asset may be in communication with the decentralizedentity 306. The blocks of the decentralized entity 306 includetransactions which are representative of the events experienced by theasset.

For example, block 330 includes transaction 1 (TX1), which may be theinitial event of the device comprising the contactless circuitry beingcoupled to the asset. In other words, the first event may be an initialevent of the device (e.g., a smartcard) providing a unique ID of thedevice and the asset it is coupled to the decentralized entity 306 to bestored as an immutable record about the asset. Each event of theplurality of events corresponds to a transaction on the decentralizedentity 306, and each transaction is obtained by the contactlesscircuitry from the decentralized entity 306 such that it may be storedlocally on the memristor 304. As such, the memristor 304 may store localblock 338 as a hash including an RND, the unique device ID (identifyingthe contactless circuitry bonded via the device to the asset), and thefirst transaction TX1 (which represents the initial event of the bondingof the device to the asset). As the lifecycle of the asset continues,more blocks are added both to the decentralized entity 306 and thememristor 304. In some examples, the transaction may be verified, and anapproval ID may be stored in the hash of the local blocks of thememristor 304 and the hash may store some information about thetransaction that occurred prior to the approved transaction.

For example, each verified hashed transaction corresponding to eachevent of a plurality of events may be stored by the memristor 304includes information about the previously stored transaction.Specifically, a second event may be the asset being installed intoanother device (e.g., the asset is a processor and the second event isthe processor installed into a laptop). The second block 332 stored inthe decentralized entity 306 may include—the second transaction (TX2)with information about the hash of the first event (e.g., the firsttransaction TX1) and the approved transaction identifier (TX ID).Similarly, the second local block 340 includes a hash including an RND,the device ID, the second transaction TX2, TX1, and the approved TX ID.

FIG. 3 illustrates an example of a third event which may be the assetbeing moved to a different geographical location (e.g., the asset is aprocessor installed into a laptop, and the laptop is shipped from themanufacture to a warehouse). The third block 334 stored in thedecentralized entity 306 may include—the third transaction (TX3) withinformation about the hash of the second event (TX2) and the approved TXID. Similarly, the third local block 342 includes a hash including anRND, the device ID, the third transaction TX3, TX2, and the approved TXID. The local blocks of the memristor 304 may be stored in this formatuntil the Nth event.

For example, FIG. 3 illustrates an example of a fourth event which maybe the asset being changing ownership to a different owner (e.g., theasset is a processor installed into a laptop, and the laptop is soldfrom the manufacture to a to a distributer). The fourth block 336 storedin the decentralized entity 306 may include—the Nth transaction (TXN)with information about the hash of the third event (TX3) and theapproved TX ID. Similarly, the Nth local block 344 includes a hashincluding an RND, the device ID, the Nth transaction TXN, TX3, and theapproved TX ID.

The local blocks stored in the memristor may be encrypted and securelystored in sequential order where the hash of the second transaction(local block 340) includes information about the first transaction(e.g., local block 338) and the first event. As the lifecycle of theasset continues, each event may be stored in the decentralized entity306 as a block and stored as a local block on the memristor 304. Assuch, the plurality of events may be represented by local blocks 338,340, 342, and 344 and stored in a heuristic format such that an end usermay track the provenance information of the asset using the data storedon the memristor 304.

The examples described in connection with FIG. 3 describe memristorbased storage of asset events where the provenance records of an assetare stored in sequential order on the memristor 304 as the data isstored on a decentralized entity 306. The local blocks 338, 340, 342,and 344 include data about the previous transaction. In this way, thememristor 304 may operate as a local blockchain storing local blocks onthe memristor 304 integrated into contactless circuitry bonded to anasset via a device such as a card.

FIG. 4 illustrates an example message flow 403 schematic for memristorbased storage of asset events consistent with the disclosure. FIG. 4illustrates a system including a card 400, a contactless circuitry 402including a radio frequency interface (RF) 410 coupled to the card 400,and a memristor 404 coupled to the contactless circuitry 402. FIG. 4illustrates a plurality of events 450-1 and 450-N, which may be referredto collectively as the events 450, a decentralized entity 406, the card400 comprising contactless circuitry 402, the RF interface 410, and thememristor 404. The card 400 may be a device similar to the device 100described in connection with FIG. 1. The card 400 may be a physicalcarrier for contactless circuitry 402 with embedded memristor 404. Thecard 400 as a physical carrier for the contactless circuitry 402 may bebonded to an asset (e.g., the asset 108 of FIG. 1) such that thememristor 404 may provide on-chip provenance records in the order inwhich the events are experienced by the asset (e.g., sequential order).

For example, the first event 450-1 may be when the card 400 is initiallybonded to the asset. When the card 400 is initially bonded to the asset,the contactless circuitry 402 of the card may generate a unique deviceID which corresponds to the contactless circuitry 402 of the card 400and the asset to which the card 400 is bonded. The first event 450-1 maybe communicated to the decentralized entity 406 as a first transaction(TX1) 452. For example, the contactless circuitry 402 may receive theTX1 452 including data from the first event 450-1 corresponding to theasset from the decentralized entity 406. The data from the first event450-1 may be information sufficient to communicate the alteration to theasset (e.g., event 1: the asset is bonded to the card). The contactlesscircuitry 402 may apply a hash function to the TX1.

For example, the contactless circuitry 402 of the card 400 may hash, at454, TX1 with the data about the first event 450-1. Specifically, theinitial hash about the first event 450-1 may include an RND, the deviceID, and TX1. Since this is the initial event the asset has notexperienced any other transactions (e.g., based on the events 450events) to hash with TX1. The card 400 may, at 456, verify TX1 with thedecentralized entity 406. For example, the card 400 may, at 458 executea smart contract by comparing the data from the first event 450-1including the hashed TX1 to conditions of the smart contract deployed onthe decentralized entity 406 to determine if the first event 450-1 is anallowable event. In other words, a smart contract may be created and/ordeployed by an entity associated with the asset. The smart contract maycomprise conditions set by the entity that created the smart contract.The conditions may relate to the asset and which events 450 arepermitted to be experienced by the asset and which events are notpermitted to be experienced by the asset.

For example, the contactless circuitry 402 may determine at 458 that thedata about the first event 450-1 abides the conditions of the smartcontract and receive an approval transaction identifier at 460 inresponse to the determination that the data about the first event 450-1abides the conditions of the smart contract and store the approvaltransaction identifier in the memristor 404 as a first local block(e.g., the local block 338). As used herein, the term “abides” refers toan event being an allowed event. Specifically, in response to theapproval TX identification 460, the asset may be modified a 462, and thecontactless circuitry 402 may store (at 464) the hashed TX1 as animmutable record (e.g., the first block 330) in the decentralized entity406 and the memristor 404 coupled to the card (e.g., as a first localblock 338). In some examples, the contactless circuitry 402 maydetermine that the first event 450-1 (and/or any event) does not abideby the smart contract.

For example, the card 400 may determine via the execution of the smartcontract that the data about the first event 450-1 does not abide theconditions of the smart contract, the card 400 may receive a rejectiontransaction identifier in response to the determination that the dataabout the first event 450-1 fails to abide the conditions of the smartcontract; and store the rejection transaction identifier to thememristor 404. The smart contract may demand conditions such as the typeof asset, the type of contactless circuitry, the specific modificationsto be implemented to the asset based on the event, etc. The smartcontract may be executed to verify the plurality of events 450 andprevent error. In some examples, the smart contract may be executed toprevent counterfeit operations, fraud, and nefarious events designed toimproperly modify an asset. As such, these events may be stored in thememristor 404 with the hash as local blocks. In this way, the provenanceinformation is stored on-chip and specific to the asset such that theycan be reviewed by a user or an owner of the asset in a heuristic formatbecause the events are stored in sequential order.

For example, the asset may experience a subsequent event, such as theNth event 450-N. The Nth event 450-N may be when the asset is altered bythe placement in another object. For example, the asset may be aprocessor bonded to the card 400 and the Nth event 450-N may be theprocessor is installed into a laptop. Because the card 400 is bonded tothe asset and includes tracking functionality such as the RF interface410, the contactless circuitry 402 may determine that the that the assetis to be modified during the Nth event 450-N. The card 400 may receive asecond transaction (TX2) from the decentralized entity 406 includingdata about the Nth event 450-N. The contactless circuitry 402 may hashthe TX2 at 468. For example, the contactless circuitry 402 may, at 468,hash TX2 with data about the Nth event 450-N and the first transactionTX1.

The card 400 may, at 470, verify TX2 with the decentralized entity 406.For example, the card 400 may compare the data from the Nth event 450-Nincluding the hashed TX2 to conditions of a smart contract deployed onthe decentralized entity 406 by executing the smart contract at 472 todetermine if the Nth event 450-N is an allowable event. In other words,a smart contract may be created and/or deployed by an entity associatedwith the asset. The smart contract may comprise conditions set by theentity that created the smart contract. The conditions may relate to theasset and which events 450 are permitted to be experienced by the assetand which events are not permitted to be experienced by the asset. Inresponse to the Nth event 450-N being an allowable event, the asset maybe modified at 476, and an approval transaction identification may betransmitted to the card 400 at 474. The approval TX identification maybe stored together with the hash of the second transaction.Specifically, at 478, the card 400, via the contactless circuitry 402,may store the hashed TX2 as a new immutable record in the decentralizedentity 406 and the memristor 404 included in the card 400 (as a secondlocal block e.g., local block 340).

The examples described in connection with FIG. 4 describe memristor 404based storage of asset events where the provenance records of an assetare stored in sequential order on the memristor 404 as the data isstored on a decentralized entity 406. A plurality of events 450corresponding to transactions of the decentralized entity 406 are hashedby the contactless circuitry 402 of the card 400 coupled to an asset.The hashed transactions are compared to smart contracts to verify thatthe events are allowable events as stipulated by the smart contract. Inthis way, the memristor 404 may operate as a local blockchain storinglocal blocks on the memristor 404 integrated into contactless circuitry402 bonded to an asset via a device such as the card 400.

FIG. 5 illustrates an example memristor 504 coupled to programmingcircuitry 522 for memristor based storage of asset events consistentwith the disclosure. Although not illustrated in FIG. 5 as to notobscure the examples of the disclosure, the memristor 504 may beintegrated into contactless circuitry (e.g., the contactless circuitry202), which may be included on a card (e.g., the card 400) bonded to anasset (e.g., the asset 108). The programming circuitry 522 may be aportion of the contactless circuitry and may be programmed withinstructions such as instructions 584, 586, 588, 590, 592, 594, 596, and598, that when executed cause the contactless circuitry to execute theinstructions.

For example, the programming circuitry 522 may include instructions 584,that when executed cause the contactless circuitry to receive a firsttransaction (e.g., the transaction 452) including data from a firstevent (e.g., the first event 450-1) from a decentralized entity (e.g.,the decentralized entity 406). For example, the data from the firstevent may be information sufficient to communicate the alteration to theasset (e.g., event 1: the asset is bonded to the card). The contactlesscircuitry may apply a hash function to the TX1. For example, theprogramming circuitry 522 may include instructions 586, that whenexecuted cause the contactless circuitry to generate a hash of the firsttransaction (e.g., the hash at 454) from the decentralized entity.Specifically, the initial hash about the first event may include an RND,a device ID, and TX1. Since this is the initial event, the asset has notexperienced any other transactions (events) to hash with TX1. Thecontactless circuitry may utilize a smart contract to verify the hashwith the decentralized entity.

For example, the programming circuitry 522 may include instructions 588,that when executed cause the contactless circuitry to verify the hash ofthe first transaction with the decentralized entity. For example, thecontactless circuitry may compare the data from the first eventincluding the hashed TX1 to conditions of a smart contract deployed onthe decentralized entity to determine if the first event is an allowableevent. In response to the verification of the hashed transaction, thecontactless circuitry may receive an approval transaction identificationto store with the hash as a local block on the memristor 504. Forexample, the programming circuitry 522 may include instructions 590,that when executed cause the contactless circuitry to store the verifiedhashed transaction on the memristor 504 coupled to the card. As such,these events may be stored in the memristor 504 with the hash as localblocks. In this way, the provenance information is stored on-chip andspecific to the asset such that they can be reviewed by a user or anowner of the asset in a heuristic format because the events are storedin sequential order.

For example, the programming circuitry 522 may include instructions 592,that when executed cause the contactless circuitry to receive a secondtransaction (e.g., the second transaction TX2 466) including data from asubsequent event (e.g., the Nth event 450-N) from the decentralizedentity. For example, the asset may experience a subsequent (e.g., asecond) event. Because the card is bonded to the asset and includestracking functionality such as the RF interface 510, the contactlesscircuitry may determine that the that the asset is to be modified duringthe second event. For example, the programming circuitry 522 may includeinstructions 594, that when executed cause the contactless circuitry tohash the second transaction from the decentralized entity, where thesecond transaction includes information about the second event. In otherwords, the hashed second transaction includes information about thesecond event and the hash (or a portion of the hash) of the firsttransaction.

The contactless circuitry may verify that the second transaction is anallowed transaction. For example, the programming circuitry 522 mayinclude instructions 596, that when executed cause the contactlesscircuitry to verify that the hashed second transaction abides a contractstored on the decentralized entity. In other words, the contactlesscircuitry may execute a smart contract on the decentralized entity toverify that the second event is an allowable event. This conformationmay be stored with the hashed second transaction as a local block.

For example, the programming circuitry 522 may include instructions 598,that when executed cause the contactless circuitry to store the verifiedhashed second transaction with the verified hashed first transaction onthe memristor 504. The examples instructions discussed in connectionwith FIGS. 1, 2, 3, 4, and 5 may be repeated for the lifecycle of theasset. In this way, a plurality of events corresponding to transactionsof the decentralized entity are hashed by the contactless circuitry ofthe card coupled to the asset. The hashed transactions are compared tosmart contracts to verify that the events are allowable events asstipulated by the smart contract. In this way, the memristor 504 mayoperate as a local blockchain storing local blocks on the memristor 504integrated into contactless circuitry bonded to an asset via a devicesuch as the card for the lifetime of the asset.

In the foregoing detailed description of the disclosure, reference ismade to the accompanying drawings that form a part hereof, and in whichis shown by way of illustration how examples of the disclosure may bepracticed. These examples are described in sufficient detail to enablethose of ordinary skill in the art to practice the examples of thisdisclosure, and it is to be understood that other examples may beutilized and that process, electrical, and/or structural changes may bemade without departing from the scope of the present disclosure.

As used herein, the designator “N”, particularly with respect toreference numerals in the drawings, indicates that a plurality of theparticular feature so designated can be included with examples of thedisclosure. The designators can represent the same or different numbersof the particular features. Further, as used herein, “a plurality of” anelement and/or feature can refer to more than one of such elementsand/or features.

The figures herein follow a numbering convention in which the firstdigit corresponds to the drawing figure number and the remaining digitsidentify an element or component in the drawing. Elements shown in thevarious figures herein may be capable of being added, exchanged, and/oreliminated so as to provide a number of additional examples of thedisclosure. In addition, the proportion and the relative scale of theelements provided in the figures are intended to illustrate the examplesof the disclosure and should not be taken in a limiting sense.

What is claimed:
 1. A device comprising: contactless circuitry toreceive data about a plurality of events corresponding to an asset; anon-volatile memory coupled to the contactless circuitry to: receive afirst transaction corresponding to a first event from a decentralizedentity; generate a representation of the first transaction, therepresentation of the first transaction including a device identifier ofthe contactless circuitry and the first transaction received from thedecentralized entity; verify the representation of the first transactionwith the decentralized entity; and store the verified representation ofthe first transaction on the non-volatile memory in a local block thatis part of a sequence of local blocks stored on the non-volatile memory,wherein the stored verified representation of the first transactionincludes information about the first event, and the local blocks of thesequence of local blocks comprise information of respective events ofthe plurality of events, and are ordered as the information of therespective events of the plurality of events are stored in correspondingblocks on the decentralized entity.
 2. The device of claim 1, whereinthe contactless circuitry is to verify the representation of the firsttransaction by comparing the representation of the first transactionwith a condition of a smart contract deployed on the decentralizedentity.
 3. The device of claim 1, wherein the ordering of the localblocks of the sequence of local blocks corresponds to an order in whichthe asset experienced the plurality of events.
 4. The device of claim 1,wherein the device is attached to the asset, and the device identifiercorresponds to the contactless circuitry and the asset to which thecontactless circuitry is attached.
 5. The device of claim 1, wherein thenon-volatile memory comprises a memristor.
 6. The device of claim 1,wherein the sequence of local blocks is part of a local blockchain inthe device, and the local blockchain corresponds to a blockchain in thedecentralized entity.
 7. The device of claim 1, wherein the contactlesscircuitry is to store the verified representation of the firsttransaction as an immutable record in non-volatile memory.
 8. The deviceof claim 1, wherein the plurality of events comprise any or acombination of: a physical modification of the asset, a change of alocation of the asset, a change in a state of the asset, and a change inownership of the asset.
 9. The device of claim 1, wherein thecontactless circuitry is to generate a digital image of the asset to bestored in the decentralized entity and the non-volatile memory when thedevice is attached to the asset.
 10. The device of claim 1, wherein thecontactless circuitry is to store the verified representation of thefirst transaction in the local block on the non-volatile memory of thecontactless circuitry as a record for the first transaction is stored ina corresponding block in the decentralized entity.
 11. The device ofclaim 1, wherein the verified representation of the first transactioncorresponding to the first event stored on the non-volatile memoryincludes information about a previously stored transaction.
 12. A cardcomprising: a non-volatile memory; and programming circuitry coupled tothe non-volatile memory, the programming circuitry comprisinginstructions to: receive a first transaction including data of a firstevent relating to an asset from a decentralized entity; generate arepresentation of the first transaction; verify the representation ofthe first transaction with the decentralized entity; store the verifiedrepresentation of the first transaction in a first local block on thenon-volatile memory; receive a second transaction including data of asecond event relating to the asset from the decentralized entity;generate a representation of the second transaction; verify that therepresentation of the second transaction abides a contract stored on thedecentralized entity; and store the verified representation of thesecond transaction in a second local block on the non-volatile memory,wherein the first local block and the second local block are part of asequence of local blocks stored on the non-volatile memory, wherein thelocal blocks of the sequence of local blocks comprise information ofrespective events of a plurality of events relating to the asset, andare ordered as the information of the respective events of the pluralityof events are stored in corresponding blocks on the decentralizedentity.
 13. The card of claim 12, wherein the ordering of the localblocks of the sequence of local blocks corresponds to an order in whichthe asset experienced the plurality of events.
 14. The card of claim 12,wherein the contract is a smart contract in a distributed ledgerimplemented by the decentralized entity.
 15. The card of claim 12,wherein the first event comprises the card providing a unique identifierof the card and the asset to the decentralized entity to be stored as animmutable record of the asset.
 16. The card of claim 12, wherein thesequence of local blocks is part of a local blockchain in the card, andthe local blockchain corresponds to a blockchain in the decentralizedentity.
 17. A system comprising: a card comprising a non-volatilememory; and a contactless circuitry including a radio frequency (RF)interface the card to: receive a first transaction including data of afirst event corresponding to an asset from a decentralized entity;generate a representation of the first transaction; store therepresentation of the first transaction as an immutable record in afirst local block on the non-volatile memory; receive a secondtransaction including data of a second event corresponding to the assetfrom the decentralized entity; generate a representation of the secondtransaction; and store the representation of the second transaction asan immutable record in a second local block on the non-volatile memory,wherein the first local block and the second local block are part of asequence of local blocks stored on the non-volatile memory, wherein thelocal blocks of the sequence of local blocks comprise information ofrespective events of a plurality of events corresponding to the asset,and are ordered as the information of the respective events of theplurality of events are stored in corresponding blocks on thedecentralized entity.
 18. The system of claim 17, wherein the orderingof the local blocks of the sequence of local blocks corresponds to anorder in which the asset experienced the plurality of events.
 19. Themethod system of claim 17, wherein the sequence of local blocks is partof a local blockchain in the card, and the local blockchain correspondsto a blockchain in the decentralized entity.
 20. The method system ofclaim 17, comprising: storing the representation of the firsttransaction in the first local block on the non-volatile memory as arecord for the first transaction is stored in a corresponding block inthe decentralized entity.